him touring the site in his regulation denims and white wooly hat, with a gaggle of fresh-faced acolytes in tow. Seeing Khalili in this quasi-mystical guise and hearing him celebrate the holiness of the earth, it is hard to believe that he was once a specialist in skyscrapers.

KHALILI'S CONVERSION CAME in 1975 when he was 37. With virtually no warning, he sold up his offices in Tehran and LA, and bought a motorcycle and set off across the mountainous hinterlands of rural Iran to study the local architecture. He was gone for five years. "Midway in my life I stopped racing with others. I picked up my dreams and started a gentle walk," is how Khalili describes it in Racing Alone, the book he wrote on his return to America. From then on, Khalili would focus exclusively on housing the poor.
        During his Iranian expedition, he not only managed to master the craft of building elegantly vaulted mud-brick buildings: he improved it. He discovered that by firing these traditional buildings for three days, effectively turning them into blazing hot kilns, they became impervious to virtually anything nature could throw at them; heat waves, snow storms, earthquakes.
        Khalili immediately recognised the potential of such buildings to meet emergencies, providing instant relief for thousands of people made homeless by wars, floods and earthquakes. Yet he continued to search for a method of construction that was simpler still.
        That's when he developed superadobe: "Now all you needed," says Khalili, "was to air-drop the sandbags into an emergency zone and put a supervisor on the ground to show local people how to build."
        The United Nations' Institute of Training and Research is championing Cal-Earth's ideas but Unitar's Nasserine Azimi admits it's a struggle convincing aid agencies that the superadobe model is worth investing in. "A lot of agencies are struck in a certain mind-set and are unwilling to try something new," she argues. "But you have a situation where 1 billion people are in temporary' housing and everybody knows this is where these people will live and die. With Cal-Earth's methods you can put up a permanent house for little more than the price of a tent. And it's housing that's sensitive to the local environment, in terms of production and the way they look."
        Despite its obvious attractions, practical application of the superadobe method has been limited. Forty Khalili designed buildings were built in Iran by the United Nations High Commission for Refugees after the Iran-Iraq war, and superadobe designs are now being used in the Caribbean, part of the effort to re-house people after Hurricane Mitch devastated the area at the tail-end of 1998.
        Artecnica, a California-based architectural firm, is planning two superadobe villages in the Dominican Republic. One, an eco-tourist resort, will pay for the construction of the other. At least that's the plan. They are also proposing to develop a Caribbean subsidiary of Cal-Earth, working with local universities, businesses and government agencies to develop more superadobe communities. The Cecropia Foundation, an environmental group backed by Woody Harrelson, is doing similar things in Costa Rica. (Other high-profile benefactors include the Grateful Dead's Rex Foundation, Ted Turner, and Aldous Huxley's widow, Laura, who has funded a Cal-Earth educational programme.)
        Khalili's latest ruse is to use the Internet to spread the word. That way, he can bypass troublesome officials and needless bureaucracy and communicate directly with people.
        Having addressed the most pressing housing problems on the planet, Khalili trained his sights on the moon. "I am interested in the moon as a solution for Earth," he says. "It's a clean slate and I'd like to keep it pure and sacred and uncontaminated by steel and smog and industrial waste. I want to show that what is there is sufficient. The moon is a mirror for everything we do here."
        He understands all too well the special challenges that building on the moon presents. There's the problem of solar particle radiation, which he proposes to tackle by making his walls five metres thick. Then there's the issue of gravity; Newton's universal force is six times weaker on the lunar surface than it is on Earth. This differential does allow Khalili to budget for buildings that are six times larger, but it also means that the tension within individual structures needs to be six times greater. The solution? To build by layering the superadobe sandbags horizontally and to use Velcro sandbags.
        His superadobe technique is the perfect model of what architects call "sustainable building". In other words, it barely taxes the environment at all. Just one coil of Khalili's sandbags will build one mile of wall material, enough to raise 20 small structures on the moon. What's more, he plans to fill the sandbags with nothing but moon dust.
        Khalili refers to himself as "a hands-on dreamer". Like the best writers of science fiction, he has a talent for endless, almost compulsive innovation. Also like the best science fiction writers, what drives him originates not from the faraway reaches of the cosmos but closer to home. "My mission," he says, "is to give dignity to the earth, so that Third World peoples who have it under their feet do not distain to build with it."
        At one end of the Cal-Earth Institute compound, off to one side of the lunar prototypes, another building is under construction. Its form is still too partial to give the game away visually, but it will eventually become a run-of-the-mill, three-bedroom, two-garage track house: "The American Dream in housing," says Khalili.
        But this track housing is being built with superadobe. The reasoning is clear: "First regular American families will live here, then you'll be able to get mortgages for them, then they'll film soap operas in them. Only then, only when America embraces earth architecture, will Third World people take pride in their own heritage."